1. Technical Field
The present invention generally relates to vehicle propulsion systems. More particularly, the present invention relates to a propulsion system for an amphibious vehicle having a continuous belt track suitable for use on water, land, snow and virtually any other terrain.
2. Discussion
Increased consumer popularity has been recently experienced in a boating market segment directed to personal watercrafts. Such personal watercrafts are typically sled-like in design and intended for use by one or two persons. An elongated cushioned seat extends above a buoyant underbody. Propulsion of conventional personal watercraft is typically provided by air jets controlled by a handle mounted throttle. Use of conventional personal watercraft is strictly limited to bodies of water of sufficient depth to float the watercraft.
Conventional personal watercraft share an aesthetic design theme with snowmobiles. Also similar is the general manner in which personal watercraft and snowmobiles are driven. Distinct from personal watercrafts, snowmobiles include a forward pair of skis and a rearward belt drive for providing a source of propulsion. The construction of conventional snowmobiles require an operating terrain of snow, ice, or the like.
These two types of vehicles typically appeal to the same market segment. Often times, owners of personal watercraft will also own snowmobiles.
Personal vehicles, including but not limited to personal watercraft and snowmobiles, are almost exclusively limited to a single operating terrain (e.g., water, snow, etc.). However, in an attempt to overcome the inherent lack of flexibility for such personal vehicles, various types of amphibious vehicles have been proposed. For example, an amphibious hovercraft have been developed which typically employ ducted air propellers for free forward motion and directional control over land, water, snow, and ice. Low speed thrust and lack of control in crosswinds or when climbing or descending steep slopes are problems which have plagued such vehicles. Air propeller performance in terms of thrust, efficiency, and noise level in terms of drivetrain and mounting have presented serious constraints to hovercraft performance and fuel economy.
Hybrid amphibious vehicles utilizing an alternative form of propulsion in the form of paddle tracks have also been proposed. However, these vehicles have proven to provide inadequate thrust and efficiency at speed over water. Hydrodynamic design considerations were over-ridden by the need for adequate traction over land, snow, ice and the like.
The present invention was developed in an attempt to overcome the disadvantages of both types of propulsion arrangements including but not limited to the disadvantages discussed above. For reasons which will become clear below, the present invention is considered inherently useful in a variety of other applications where propulsion over multiple types of terrain is desired. Thus, the present invention is not to be regarded as being limited to application for personal amphibious vehicles.